The present invention relates to a frame for an agricultural trailer vehicle.
Vehicle frames which are supported via the mountable wheels on the ground and carry units and devices corresponding to the objects of the vehicles are generally known. Usually two longitudinal supports are arranged at a transverse distance from one another and fixedly connected with a front and a rear transverse support to a rectangular frame. The horizontal orientation of this frame with the longitudinal supports and the transverse supports which are the same height and extend parallel to one another, leads to the fact that the frame over its whole length has a width corresponding to the length of the transverse support.
Such horizontal frames (width frames) have the difficulties in that the wheels are arranged laterally outside the longitudinal support, and the lateral wheel freedom is limited by the outer edges of the longitudinal support. In interest of a rational operation the trend for further increasing transport loads, so that the vehicle with high total weight runs on the agricultural fields. This requires however wider wheels in order to prevent the increase of ground pressure or the ground compacting over an average value. Suitable wide tires or wide wheels are also available, they are however not acceptable for a wide vehicle frame which must be maintained within permissible vehicle width to be used in open streets, as long as there is no special permission for this.
The German document DE 159 150 discloses a cross-country vehicle in which instead of a rectangular frame, an H-frame is disclosed with a single centrally extending longitudinal support of substantially square cross-section. It is formed U-shaped with an open upper side and crosses a front as well as rear transverse carrier extending between both wheels of the front or the rear wheel pair. The longitudinal support has in the region of the transverse carrier and thereby both wheel axes a substantially increased height, and the intersecting supports in the intersecting regions have a joint lower side. In both constructions the frames are small in their central region between both transverse supports. However, it deals with a horizontal frame (width frame) in which the front wheels as well as the rear wheels are arranged again at a distance corresponding to the length of the transverse support.
The German document DE-C 38 18 200 discloses an agricultural multi-purpose vehicle with a hollow profile frame. It has a single centrally extending longitudinal support of a square cross-section (maximum 50.times.50 cm), in which the rigid rear wheel axis and the swinging and pivotally formed front wheel axis are supported. For avoiding a high ground pressure it has wide wheels. The rear wheels have a diameter of more than 1.6 m and the width of from 1.0 to 1.3 m so that a wide rear wheel roller is formed, which is interrupted only by the longitudinal support. This multi-purpose vehicle is an automatic driver with a drive of both axes and with a driver cabin on the front region and the alternating attachments in the central and rear region of the vehicle frame. The longitudinal support has a square profile which remains the same over its whole length. In order to provide the required strength the profile of the longitudinal support must have a relatively great wall thickness and the average dimensions of the transverse cross-sectional profile must be maintained. The frame is therefore expensive and always has a width which poses an obstacle.